Vehicles equipped with passive entry, passive start (PEPS) functionality are known in the art. With conventional PEPS systems one or two keyless fobs are associated with a given vehicle. Such PEPS vehicle systems generally include a body control module or BCM in the vehicle which is operable to lock and unlock the vehicle doors, release the truck latch, start-up and turn off the engine, hook the horn and other auxiliary vehicle functions. The body control module is also operable to communicate with the keyless fob to activate these vehicle functions.
The PEPS system communicates in one of two modes. In a first mode, a passive command is communicated between the keyless fob and the BCM as a LF signal such that a passive entry is enabled simply by lifting the door handle or a passive start is enable by pushing a start button on the instrument panel. Such passive commands require the keyless fob to be in close proximity with the BCM. In a second mode, an active command is communicated between the keyless fob and the BCM as an RF signal such that an active lock/unlock or a remote engine start is enabled by pushing a button on the keyless fob. Such active commands may be carried out when the keyless fob is a substantial distance from the BCM.
In a PEPS system, such as described above, the BCM interrogates or polls the area immediately around the vehicle using the LF signal to determine how many keyless fobs are within a given response zone. Any keyless fob within this area will respond to the interrogation. If multiple fobs respond, then an overlap or collision of the respective responses may occur requiring repeated interrogation and delayed authentication.
Accordingly, it is desirable to provide a robust method for an unlimited number of PEPS keyless fobs to respond, particularly in fleet vehicle applications, without adversely impacting the overall PEPS authentication time period. In addition, it is desirable to ensure that regardless of the number of keyless fobs within the response zone, the latency time for a single passive challenge event is not increased. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.